Minor details – they must have a site to do that. Here in the Great Lakes, we have Boat Nerd and we can hunt down when freighters (and likely tug barges as well) are expected at their next unloading port. We used to use it before cellphones were popular and our freighter clients were only able to get a signal in port if not too much interference at the port … and no signal when out “at sea” … bet you have something comparable there.